“There aren’t words to describe how I can possibly thank my beautiful friend Francia Raisa,” Gomez wrote, along with a photo of them clutching each other’s hand as they sat side by side in their hospital beds. “She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much sis.”

For her part, Raisa said she was “beyond grateful that God would trust me with something that not only saved a life, but changed mine in the process… Love you sis, so glad we’re on this journey together.”

The friendship between Selena, 25, and Francia, 29, started 14 years ago. Francia, who appeared on the show The Secret Life of the American Teenager and will soon be co-starring in Yara Shahidi’s Black-ish spin-off, Grown-ish, has said that they met while doing charity work at Children’s Hospital Los Angeles.

She elaborated in an interview with Latina magazine in 2013, saying, “Disney and ABC Family had the stars of their shows go to the Children’s Hospital. Selena and I were in the same group and we just clicked.” That same year, Raisa also said on Instagram, “Met you when you were 15 and u became family to me when you were 16. Since then you have changed my life and I’ve become a better person.”

Their bond was so strong, there was even friendship jewelry involved. Gomez gave Raisa “a sister is a forever friend” necklace soon after their meeting. Raisa, whose dad is American radio personality Renán Almendárez Coello, refers to her pal Gomez as her “lil sis.”

The women often pop up on each other’s Instagram feeds. Raisa, who is also a singer like the Weeknd’s ladylove, is so special that she gets her very own birthday tribute posts.

And vice versa — with hot wings!

Even cuter? They do dance routines and stuff.

Their personal relationship extends into the professional realm with them supporting each other’s career.

Everyone should watch @therealfrancia on the season premiere of Secret Life tonight

And supporting each other in general as they go through life’s ups and downs, obviously including Gomez’s illness, which she went public with in 2015, as well as relationship woes. (We imagine they’ve had many heart-to-hearts over Justin Bieber.)

They have also been each other’s plus-ones to many events. Here they are at the Unlikely Heroes’ 3rd Annual Awards Dinner and Gala in 2014.

Their hangs also include concerts. Here they are leaving a Beyoncé show in 2013.

Since news broke of Raisa’s amazing act of friendship in donating her kidney, Gomez’s fans have been showing Raisa so much love on social media. Raisa’s post about it, which came several hours after Gomez originally shared the news of her secret operation, noted that they will soon tell more of the story, but directed fans to Lupus Research Alliance for more information about the autoimmune disease.